Frogger works great on my towered A1200, 68060 50Mhz, 96K ram, with a mediator board and Voodoo 3 card. I have tried various formats (Avi, Mov, Mpeg) and i could play them all at fullscreen with no problem, even in a window stretched to fullscreen (in my case 800 x 600). It uses the Vlayer capability of a graphics cards to allow scaling with no overhead on the CPU, the CPU is used soley for decoding! To answer one question Mpeg (video and audio) is decoded in software and not hardware.
The only problem for people who are going to download frogger is the shareware restriction, it only plays the first 30% of the file. If you want it all you have to register, just under £10 in UK money. There are only two sharware programs i have ever registered 'WHDLoad' and 'Frogger', both of these have had a lot of work put into them and are worth every penny!